Fermented foods have never been so readily available in our supermarkets. From kimchi to kefir, sourdough bread bakeries and kombucha taps in cafes, there is an increasing supply of live fermented foods to choose from.
Exploring the World of Fermented Foods: What Are They and Why Include Them?
The Science Behind Fermentation: How Microorganisms Transform Foods
Fermented foods and beverages are foods which have undergone controlled microbial growth and fermentation (1). Fermentation is the process by which microorganisms such as yeast break down carbohydrates in foods to produce acid and compounds such as glucose and ethanol found in alcohol. This gives fermented foods their unique taste. Fermentation has been around for thousands of years and is used as a preservation technique to extend the shelf life of many fresh foods. One of the most common examples of this is sauerkraut – which is cabbage that is fermented in salt.
Prebiotics and Probiotics: Understanding the Gut-Health Connection
The Role of Prebiotics and Fermentation in Gut Health
Plant foods are rich in prebiotics, but when they undergo the process of fermentation to help nourish and feed the probiotics. Many plant foods in our everyday diet, like nuts, seeds, fruit, vegetables and whole grains, are examples of prebiotics. Foods which contain probiotic strains and live cultures include yoghurt – you might commonly see these advertised as ‘live’ or ‘bio’ yoghurt. This is because they contain strains of bacteria such as Lactobacillus, Bifidobacterium and Streptococcus, which are beneficial for our gut microbiota profile and can help improve our immunity. This is because 70% of our immune system is found in our gut!
Balancing Fermented Foods and Plant-Based Diet
In order to support our gut health, recent evidence has recommended that we eat fermented foods alongside a variety of fruits, vegetables, nuts, seeds, pulses, legumes and whole grains. The American Gut Project (2) found that people should aim to include 30 or more plant foods in our diet each week and at least one fermented food daily. Other fermented foods include sauerkraut, kimchi, miso and tempeh.
Menopause and Fermented Soy Foods
In terms of menopause, the role of plant phytoestrogens in reducing the severity and frequency of hot flashes in women during menopause has been discussed in a separate blog post. However, the addition of fermented soy foods such as tempeh and miso has been specifically studied in menopausal women as oestrogen declines during this life stage. Studies have found that 100g of high-quality soy goods such as tofu, tempeh and soy milk and 1 – 2 tablespoons of milled or ground flaxseeds can support a reduction in menopausal symptoms (3). While the verdict is still out on the precise impact of fermented soy foods on menopausal symptoms, there is no reason not to include them within your diet if you feel they benefit you!
Embracing Dietary Diversity – Fermented Foods for Gut Health and Menopause
Everyone can benefit from increasing their intake of vegetables and fermented foods as they are rich in dietary fibre, pre and probiotics, antioxidants and phytochemicals. Probiotics from dairy products such as kefir and yoghurt contain an additional boost of nutrients, including calcium and protein, which are important nutrients for women, especially to protect bone health during and after menopause. The current research base on evidence surrounding fermented soy foods and menopausal symptoms needs further consideration, however, these foods can offer additional variety, taste and enjoyment to your diet, so eat up!
References
- Marco, M.L., et al., Health benefits of fermented foods: microbiota and beyond. Current opinion in biotechnology, 2017. 44:94-102.
- The American Gut Project. Available on: https://www.mymicrobiome.info/en/news-reading/the-american-gut
- Franco OH et al (2016) Use of Plant-Based Therapies and Menopausal Symptoms: A Systematic Review and Meta-analysis. JAMA 315: 2554-2563Crawford AL et al (2013) The impact of dose, frequency of administration, and equol production on efficacy of isoflavones for menopausal hot flashes: a randomised pilot trial. Menopause 20: 911–921.
